Upgrade built-in storage to SAN

[Thomas_VDB]

Hi,

We have 2 HP Proliant ML350 servers (1x G6 and 1x G5).
Each server is running VMWare ESXi independantly. They have their own built-in SAS-hotswappable drives, where the VM's are stored. They are used in our company (20 clients), and have about 6 VM's running, SBS2008 being one.

I would like to create a VM cluster from these 2 servers, which requires shared storage such as a SAN.
I would like to use an iSCSI SAN with sata drives, such as an Iomega Storcenter.

2questions regarding this :
- can anyone give me an indication (ballpark) if switching from built-in storage to such a gigabit iSCSI SAN will give noticable slower performance for the users?
- Do I need special add-in cards on the server or can I just use the built-in NIC?

Thanx!
Thomas.

[Johan Guldmyr]

Hey!

There are 10GbE iSCSI SANs these days.
There are also the Ethernet NICs with TCP Offload Enginer/Chimney around that you may want to look into. Some vendors also have some kind of iSCSI multifunction/accelerator card.

The SAS drives you have at the moment - how many, what raid level and what raid card? Do you have a BBWC connected to it?

In VMWare/Guest OS:s you are using - is it hard to measure the amount of i/o or MB/s that your current setup is using and then you can use that to size the storage you need?

[Thomas_VDB]

Hi,

Thanks for your quick reply. Some answers to your questions :
- 10gbE iSCSI : i think these are pretty high-end solutions and we 're not really looking for that. Just looking for an affordable iSCSI solution. Also the reason why I am looking into the iomega storcenter in stead of the P4000 from HP.
- iSCSI NIC's : looks interesting. I googled around and found the Broadcom NetXtreme II. About 250â ¬.
- Our ML350 G6 has 300GB SFF SAS drives in Raid5.
- Measuring the current situation : I'll try this.

Nevertheless I would like to know if such a 1gbE SAN will do for a small company with about 20 clients where SBS2008 is the main VM.

[Johan Guldmyr]

Hi, OK, I've never done an upgrade like this so I hope somebody else reads this post and can answer :)

The 300GB in R5, are the 15k? How many in each ML350?

Found this one: http://h30144.www3.hp.com/SWDSizerWeb/default.htm

But looks like you'll need a HP sales person to help you out with that.

Of course, why not get in touch with HP sales anyway and say that you're looking into upgrading it and primarily on the iomega - maybe they'll give you a good offer on something else? :)

[Zygmunt Krawczyk]

From performance point of view, the best solution is to upgrade to the SAS shared solution. Good solution is HP P2000sa SAS SFF array - shared SAS storage for up to 8 hosts in single SAS link or up to 4 hosts with dual (redundant) SAS links. One of the benefit from using HP P2000sa SAS SFF array is that you can move your SAS SFF disks to the array. P2000sa SFF array uses Proliant SFF disks. You need to buy the following (for dual redundant links):

1 x AW594A HP StorageWorks P2000 G3 SAS MSA Dual Controller SFF Array System
2 x 614988-B21 HP SC08e 6Gb SAS HBA
4 x 407339-B21 HP Ext miniSAS to miniSAS 2m Cable

[Johan Guldmyr]

Oh, I was under the impression that the disks were not the same between the MSA2000/P2000 and the Proliants.

Before the MSA2000 disks were usually Dual Port and the Proliants were usually Single Port - has this changed? Are the SAS SFF always dual port?

But true, the P2000sa does 6G I believe (you'll need new cards yes), there is iSCSI controller for the P2000 and I believe quite recently HP released a 10GbE iSCSI controller too.

[Thomas_VDB]

Hi,
thanks for your reply!

Indeed I was looking into the HP storageworks SAN solutions. The P2000 indeed looks interesting but it is approx. 5x more expensive than the Iomega 8TB solution and it comes without disks.
Can you give me the advantages of the P2000 over the Iomega storworks? I guess the fibre in stead of gigabit ethernet connection is one.

[Johan Guldmyr]

Could you provide a link to the iomega?

P2000 g3 specs are here:

http://h18000.www1.hp.com/products/quickspecs/13551_div/13551_div.html

[Thomas_VDB]

Thanx, looks promising.

One last question though :
4 years ago , we bougth our G4 server, which had U320 disks. Our G5 had SAS LFF disks, and our G6 now has SAS SFF. Keeps changing...
Do you have an idea whether these SAS SFF disks will remain a standard for the next 5 years or so? Because we would like to invest in this kind of SAN, and keep using this SAN while we replace the server each 2 years or so.

[Zygmunt Krawczyk]

>> Oh, I was under the impression that the disks were not the same between the MSA2000/P2000 and the Proliants.

SFF disks are the same, LFF disks are not.

>> Before the MSA2000 disks were usually Dual Port and the Proliants were usually Single Port - has this changed? Are the SAS SFF always dual port?

Currently all SAS SFF Proliant disks are dual port. In Proliants one port only is used, in MSA2000/P2000 and MSA70/D2000 dual domain both ports are used.

[Johan Guldmyr · Accepted solution]

That's a hard one!

What about these SSD disks? Maybe the server disk will also get the models with a builtin SSD/flash or something.. Or maybe they will get a lot bigger as well.

But at least the G6 and G7 (same for two generations) have SFF disks and as far as I know the largest SFF is now 600GB? I read on theregister the other day that this year we may see 900GB SFF disks.

Do you know if your storage requirements will expand beyond the limits of the P2000 in five years? :)

If you feel it's deserved, don't for get to give points to posts in this forum if ;)

[Zygmunt Krawczyk]

SFF SAS disks were introduced with G5 servers (eg. DL360 G5, DL380 G5) and are continued with G6 and G7. Moreovers the same disks are adopted in storage systems (MSA50, MSA70, D2700, MSA2000 SFF, P2000 SFF) and will be used in new storage systems. I believe, that current HP SAS SFF standard will not change in HP systems for more than next 5 years. Probably the speed will increase to 12Gb, but it should be backward compatible with 6Gb and 3Gb.

[Thomas_VDB]

Hi,

Learned a lot thanks to this thread.

Question regarding the HP P2000 SAN that was recommended.
I am reading that this SAN comes in 3 configurations : with a fibre channel, with a SAS connection or an iSCSI connection.

Why did you recommend the SAS-configuration? Is it because I have a SAS controller in my Proliant? Is iSCSI or Fibre not a more standard solution if I want to add more host-servers later to the pool?

[Zygmunt Krawczyk]

>> I am reading that this SAN comes in 3 configurations : with a fibre channel, with a SAS connection or an iSCSI connection.

P2000 is offered in the following host connection:

1) SAS 6Gb (each controller has 4 SAS 6Gb ports, total 8 ports, each port has four 6Gb lanes, total 32 6Gb lanes, total througput 192Gb)

2) FC 8Gb (each controller has 2 FC 8Gb ports, total 4 ports, total throughput 32Gb)

3) 1Gb iSCSI (each controller has 4 iSCSI 1Gb ports, total 8 ports, total throughput 8Gb)

4) 10Gb iSCSI (each controller has 2 iSCSI 10Gb ports, total 4 ports, total throughput 40Gb

5) conbined FC 8Gb and 1Gb iSCSI

>> Why did you recommend the SAS-configuration? Is it because I have a SAS controller in my Proliant? Is iSCSI or Fibre not a more standard solution if I want to add more host-servers later to the pool?

For configurations up to 8 hosts, the P2000 SAS array is the cheapest solution with highest performance. For more hosts you can consider iSCSI (less performance, more hosts) or FC (much higher costs, more hosts).

[Michael A. McKenney]

We went with a MSA 2012fc SAN and two Cisco MDS-9124 fabric switches. The SAN is 4 Gbps dual channel fiber based. I would not go slower than this for storage to multiple servers.

If you want a inexpensive solution a NAS is OK. 1 Gbps will be slow for two servers to access. You might end up regretting such slow storage for backups.

[wobbe]

The reason for using a SAN is to be able to use VMWare features like vmotion and ha.
Since you have two different type of server I doubt that these features will work.

[Thomas_VDB]

why would ha and vmaotion not work if my servers aren't equal. The whole idea of vmware is being hardware independent, isn't it?
Off course performance would be optimal when replacing a G6 by a G5.

[Michael A. McKenney]

I looked at a C7000 Blade Center with VMWare. 5 blades, dual 8 core AMD Opterons, 64GB RAM, dual fiber HBAs, 10 Gbps NIC to Flex-10. VMWare would be able to use the 80 cores, 300+ GB of RAM how ever it wanted to load balance.

Using VMWare on a single server can pose problems. You still need cores and RAM for each application. VMWare also has overhead. I saw a server with a single quad core, 16GB of RAM trying to run four VM Servers with Exchange and SQL. They needed a lot more cores and probably 64GB of RAM.

VMware can leverage hardware. You also need to make sure you have adequate resources.

A SAN allows multiple servers to load from VMWare. You setup all your LUNs for each server. SANs are faster than a NAS or regular RAID because of the dual channel drives, large cached controllers, bandwidth to the HBAs.

You also need more NIC network bandwidth to run mutliple VMWare sessions. Do you want to share four servers on 4 x 1 Gbps teamed connections. My Exchange and SQL server both have 4 x 1 Gbps teamed NICs. The C7000 would have 10 Gbps per blade. On a single server, you will be cruxifying network performance with VMWare on 4 Gbps NIC team. You have to share resources.

[Alzhy]

Ballpark?

It depends on how I/O intensive are your VMs or if there are periods wherein ALL VMs will be hyperactive at once.

What sort of iSCSI SAN ? HomeBrew (OpenFiler) or one of the zillions of SMB NAS/iSCSI arrays out there?

If you are hell bent on proceeding, I suggest you use multiple trunked/bonded and isolated Networks for your iSCSI network and private LAN (vMotion).

I too have 2 ML350 G6's... As I could not afford the vMware HA License - I decided to go with Linux/KVM as my hypervisor and HA solution. I used CenTOS. It was an easy conversion of the VMs to KVM format. I built my own OpenFiler iSCSI array using Black Edition WD SATA Drives. 2x1Gbit bonded NICs for the iSCSI connections, 2x1Gbit Private LAN for vMotion and 2x1Gbit Client LAN connections... Worked out uber Kool.

VMs consist of:

SME Server 7.X File Server
Win2k3 SBS
Win2k3 App Server
Centos Mail/HTTP Server
2 Windows 7 Enterprise Desktops

[Wayne Henegar]

I have found this thread very interesting as I am looking at a 2-4TB SAN solution to use with HyperV. Some of you are recommending the P2000. How does it compare to the X1600 with SFF SAS drives? In features and cost.